As the commercial use of seaweed for natural product extraction calls for abundant, uniform biomass, this study focused on
the production and the variability of the harvested biomass of valuable compounds produced by a commercially relevant
red algal species, Asparagopsis armata. Its tetrasporophyte stage was retrieved from two Irish localities and grown for over
2 years in indoor cultures at 13 °C and 17 °C, and bromoform, mycosporine-like amino acids and phycobiliprotein contents
were monitored over time. Growth rates at diferent temperatures were specifc to isolates, and one isolate failed to grow at
17 °C. All compounds of interest were detected by the end of the 2-year cultivation period, and most of them were produced
at an exponential rate at 13 °C but not at the higher temperature. At 13 °C, bromoform reached concentrations of 10.00 ±
0.55 mg g−1, total mycosporine-like amino acids of 2.65 ± 0.10 mg g−1, phycoerythrin of 11.46 ± 0.35 mg g−1 and phycocyanin of 72.13 ± 1.74 mg g−1 in Irish isolates. The observed variability in compound content was statistically signifcant
but not large enough to impede commercial utilization. Bromoform content in cultivated samples was almost 6-fold higher
than in feld-collected samples though natural bromoform variability remains to be elucidated. Our fndings suggest that
the tetrasporophytic phase of A. armata is a suitable candidate for indoor cultivation; abundant and homogeneous biomass
composition can be obtained which can be further optimized by growth temperature.
